First, I’d like to try to determine Fonzie’s worth. He had an OPS+ of 121 last year, following years of 114 and 104. Soriano only plays around 140 games a year at this point, but he’s been more durable than people might imagine. His last season wasn’t really fluky at all: his BABIP was exactly his career average, his LD% and HR/FB both at normal levels. It seems as safe as it can be for a player going into his age-37 year that he will be a solid producer. He even plays a passable LF (though BRef hates his defense)!

Fangraphs had Soriano as a 4 WAR player last year, only 1.4 the year before that, and 3.2 the year before that one. I’d say Soriano is a good bet to provide 2.5 WAR next year, and 2 WAR the year aftewards.

If you assume a win on the open market is around $4.5 million dollars, then it stands to reason that a player with 2.5/2 in the toolkit should get right at 2/$20. The Cubs, of course, are paying more than that, but would gladly eat enough of the contract to get that number to 2/$10 for a prospective trade partner.

So, we’ve established that trading Soriano (and leaving the other team to pick up 2/10) provides the Cubs with about $10 million dollars of surplus value. What sort of prospect could that buy?

If we use this handy guide, we could get a B grade pitcher (by Sickels), or around a 75-100 pitching prospect in baseball (so think the bottom of the Top 200) list. For the Cubs, think a Dillon Maples or Pierce Johnson type (who are B-).

That’s a greater return than I would have thought, at first; then I sort of realized how good of a player Soriano has really been. If you strip away his contract, he’s been a very productive player (if overpaid). Similar talents on the market (Victorino, Hunter) have gotten bigger deals. Why shouldn’t 2 years and 10 million for Soriano be worth a Pierce Johnson type?

If Soriano is worth a prospect in the global 150-200 range, that’s about the 5-7 range for an average individual team. Domonic Brown would have been way more than that in 2011 (when he was the #4 prospect in baseball). However, Brown is injury-prone (he hurt his left knee again this year). He spent another unproductive third of a season at the major league level, and did not really dominate in AAA last year (although the IL is the pitcher’s league). Brown plays a above-average defense in right, but is a hair below average in centerfield (where he’d presumably play for the Cubs).

All in all, I’d wager Brown is a prospect in the 75-100 range next year, if not a shade lower. That is slightly more expensive than Soriano is worth; however, you’re paying for the upside that Soriano could provide (a 3.5 or 4.0 WAR season is easily in his capabilities), and getting a player that fits into the Phillies’ tight budget. I’d say a Soriano for Brown swap works for both sides, and if we have to throw in a C-level prospect or two to make that happen, I’m very fine with that too.